1-Thiadiazolyl-5-acylimidazolidinones

ABSTRACT

This invention discloses new compounds of the formula ##STR1## wherein R 1  is selected from the group consisting of alkyl of up to 3 carbon atoms, cycloalkyl, alkenyl, chloroalkyl, bromoalkyl, alkoxy, alkylthio, alkylsulfonyl and alkylsulfinyl; R 2  is selected from the group consisting of alkyl, alkenyl, haloalkyl and ##STR2## wherein R 4  and R 5  are each selected from the group consisting of hydrogen and alkyl; and R 3  is selected from the group consisting of alkyl, alkenyl, haloalkyl, alkynyl, alkoxyalkyl, cycloalkyl and ##STR3## WHEREIN X is selected from the group consisting of alkyl, alkoxy, halogen, haloalkyl, alkylthio, nitro and cyano; n is an integer from 0 to 3; and m is the integer 0 or 1. Further disclosed is the herbicidal utility of the foregoing compounds.

This invention relates to new compositions of matter and morespecifically relates to new chemical compounds of the formula ##STR4##wherein R¹ is selected from the group consisting of alkyl of up to 3carbon atoms, cycloalkyl, alkenyl, chloroalkyl, bromoalkyl, alkoxy,alkylthio, alkylsulfonyl and alkylsulfinyl; R² is selected from thegroup consisting of alkyl, alkenyl, haloalkyl and ##STR5## wherein R⁴and R⁵ are each selected from the group consisting of hydrogen andalkyl; and R³ is selected from the group consisting of alkyl, alkenyl,haloalkyl, alkynyl, alkoxyalkyl, cycloalkyl and ##STR6## WHEREIN X isselected from the group consisting of alkyl, alkoxy, halogen, haloalkyl,alkylthio, nitro and cyano; n is an integer from 0 to 3; and m is theinteger 0 or 1.

The compounds of the present invention are unexpectedly useful asherbicides.

In a preferred embodiment of this invention R¹ is selected from thegroup consisting of alkyl of up to 3 carbon atoms, cycloalkyl of from 3to 7 carbon atoms, lower alkenyl, lower chloroalkyl, lower bromoalkyl,lower alkoxy, lower alkylthio, lower alkylsulfonyl and loweralkylsulfinyl; R² is selected from the group consisting of lower alkyl,lower alkenyl, lower haloalkyl and ##STR7## wherein R⁴ and R⁵ arehydrogen or alkyl of up to 3 carbon atoms; and R³ is selected from thegroup consisting of lower alkyl, lower alkenyl, lower haloalkyl, loweralkynyl, lower alkoxyalkyl, cycloalkyl of from 3 to 7 carbon atoms and##STR8## wherein X is selected from the group consisting of lower alkyl,lower alkoxy, halogen, lower haloalkyl, nitro, cyano and loweralkylthio; n is an integer from 0 to 3; and m is the integer 0 or 1.

The term "lower" as used herein designates a straight or branched carbonchain of up to six carbon atoms.

The compounds of the present invention can be prepared by reacting acompound of the formula ##STR9## wherein R¹ and R² are as heretoforedescribed, with an acid anhydride of the formula ##STR10## wherein R³ isas heretofore described, in the presence of a catalytic amount ofp-toluenesulfonic acid. This reaction can be effected by combining thereactants and the catalyst at room temperature in an inert organicreaction medium and then heating the reaction mixture on a steam bathwith stirring for a period of from 1/2 to 4 hours. After this time thereaction mixture can be cooled and the desired product can be recoveredby filtration if formed as a precipitate or upon evaporation of theorganic reaction medium if soluble therein. In some instances the acidanhydride can be used as a solvent for the compound of formula II,obviating the use of an inert solvent as the reaction medium. When loweralkanoic anhydrides are used, water can be added to the reaction mixtureto precipitate the desired product upon completion of the reaction. Theproduct can then be purified by conventional means such asrecrystallization and the like. In some instances the foregoing reactionresults in the formation of a mixture of products consisting of thedesired compound of this invention and dehydrated starting material ofthe formula ##STR11## wherein R¹ and R² are as described. In theseinstances the desired product can be isolated by fractionalprecipitation.

The compounds of this invention can also be prepared by reacting thecompound of formula II with an acid halide of the formula ##STR12##wherein R³ is as heretofore described, in the presence of an acidacceptor such as a tertiary amine. The preparational method can beutilized when the desired anhydride of formula III is not available.This reaction can be effected by slowly adding the acid chloride offormula V with stirring to a solution of an about equimolar amount ofthe compound of formula II in an inert organic solvent, in the presenceof an acid acceptor, at a temperature of about 10° to 30° C. After theaddition is completed the reaction mixture can be heated at atemperature ranging up to the reflux temperature of the mixture toensure completion of the reaction. The desired product can then berecovered by first filtering the reaction mixture to remove acidacceptor chloride, followed by stripping off the solvent if the productis soluble therein, or, if formed as a precipitate, by filtration andsubsequent washing and purification.

The compounds of formula II can be readily prepared by heating acompound of the formula ##STR13## wherein R¹ and R² are as heretoforedescribed, in a dilute, aqueous, acidic reaction medium for a period ofabout 10 to about 60 minutes. Temperatures of from about 70° C. to thereflux temperature of the reaction mixture can be utilized. The reactionmedium can comprise a dilute aqueous inorganic acid such as hydrochloricacid at a concentration of from about 0.5 to about 5 percent. Uponcompletion of the reaction the desired product can be recovered as aprecipitate by cooling the reaction mixture. This product can be used assuch or can be further purified by conventional means such asrecrystallization and the like.

The compounds of formula VI can be prepared by reacting a molar amountof an isocyanate dimer of the formula ##STR14## wherein R¹ is asheretofore described, with about two molar amounts of a dimethyl acetalof the formula ##STR15## wherein R² is as heretofore described. Thisreaction can be effected by heating a mixture of the isocyanate dimerand the acetal in an inert organic reaction medium such as benzene atthe reflux temperature of the reaction mixture. Heating at reflux can becontinued for a period of from about 2 to about 30 minutes to ensurecompletion of the reaction. After this time the desired product can berecovered upon evaporation of the reaction medium and can be used assuch or can be further purified by standard techniques in the art.

The isocyanate dimer of formula VII can be prepared by reacting athiadiazole of the formula ##STR16## wherein R¹ is as heretoforedescribed, with phosgene. This reaction can be effected by adding aslurry or solution of the thiadiazole, in a suitable organic solventsuch as ethyl acetate, to a saturated solution of phosgene in an organicsolvent such as ethyl acetate. The resulting mixture can be stirred atambient temperatures for a period of from about 4 to about 24 hours. Thereaction mixture can then be purged with nitrogen gas to removeunreacted phosgene. The desired product can then be recovered byfiltration, if formed as a precipitate, or upon evaporation of theorganic solvent used if soluble therein. This product can be used assuch or can be further purified as desired.

Exemplary thiadiazoles of formula IX useful for preparing the compoundsof the present invention are 5-methyl-2-amino-1,3,4-thiadiazole,5-ethyl-2-amino-1,3,4-thiadiazole, 5-propyl-2-amino-1,3,4-thiadiazole,5-t-butyl-2-amine-1,3,4-thiadiazole, 5-allyl-2-amino-1,3,4-thiadiazole,5-pent-3-enyl-2-amino-1,3,4-thiadiazole,5-chloromethyl-2-amino-1,3,4-thiadiazole,5-β-chloroethyl-2-amino-1,3,4-thiadiazole,5-γ-chloropropyl-2-amino-1,3,4-thiadiazole,5-trichloromethyl-2-amino-1,3,4-thiadiazole,5-trifluoromethyl-2-amino-1,3,4-thiadiazole,5-methoxy-2-amino-1,3,4-thiadiazole, 5-ethoxy-2-amino-1,3,4-thiadiazole,5-propoxy-2-amino-1,3,4-thiadiazole,5-butyloxy-2-amino-1,3,4-thiadiazole,5-hexyloxy-2-amino-1,3,4-thiadiazole,5-methylthio-2-amino-1,3,4-thiadiazole,5-ethylthio-2-amino-1,3,4-thiadiazole,5-propylthio-2-amino-1,3,4-thiadiazole,5-butylthio-2-amino-1,3,4-thiadiazole,5-methylsulfonyl-2-amino-1,3,4-thiadiazole,5-ethylsulfonyl-2-amino-1,3,4-thiadiazole,5-butylsulfonyl-2-amino-1,3,4-thiadiazole,5-methylsulfinyl-2-amino-1,3,4-thiadiazole,5-ethylsulfinyl-2-amino-1,3,4-thiadiazole,5-propylsulfinyl-2-amino-1,3,4-thiadiazole,5-butylsulfinyl-2-amino-1,3,4-thiadiazole and the like.

Exemplary suitable acetals of formula VIII for preparing the compoundsof this invention are the dimethyl acetal of 2-methylaminoacetaldehyde,the dimethyl acetal of 2-ethylaminoacetaldehyde, the dimethyl acetal of2-propylaminoacetaldehyde, the dimethyl acetal of2-butylaminoacetaldehyde, the dimethyl acetal of2-pentylaminoacetaldehyde and the dimethyl acetal of2-hexylaminoacetaldehyde.

Exemplary suitable acid anhydrides of formula III are acetic anhydride,propionic anhydride, butanoic anhydride, pentanoic anhydride, hexanoicanhydride, acrylic anhydride, butenoic anhydride, pentenoic anhydride,chloroacetic anhydride, bromoacetic anhydride, β-chlorobutanoicanhydride, cyclohexylcarboxylic anhydride, benzoic anhydride, toluicanhydride, 4-chlorobenzoic anhydride, 3-bromobenzoic anhydride,4-fluorobenzoic anhydride, 4-methoxybenzoic anhydride, 4-ethoxybenzoicanhydride, 4-chloromethylbenzoic anhydride, 4-trifluoromethylbenzoicanhydride, 3,4,5-trichlorobenzoic anhydride, 3-methylthiobenzoicanhydride, 3-ethylthiobenzoic anhydride, 4-butylthiobenzoic anhydride,phenylacetic anhydride, 4-methylphenylacetic anhydride, propynoicanhydride, butynoic anhydride, methoxyacetic anhydride,β-methoxypropionic anhydride, γ-ethoxybutanoic anhydride and the like.

Exemplary suitable acid chlorides of formula V useful for preparing thecompounds of the present invention are the acid halides of the sameacids as set forth above in the examples of acid anhydrides.

The manner in which the compounds of the present invention can beprepared is more specifically illustrated in the following examples.

EXAMPLE 1 Preparation of 5-Methyl-1,3,4-thiadiazol-2-yl Isocyanate Dimer

A saturated solution of phosgene in ethyl acetate (100 ml) is chargedinto a glass reaction vessel equipped with a mechanical stirrer. Aslurry of 5-methyl-2-amino-1,3,4-thiadiazole (40 grams) in ethyl acetate(300 ml) is added to the reaction vessel and the resulting mixture isstirred for a period of about 16 hours, resulting in the formation of aprecipitate. The reaction mixture is then purged with nitrogen gas toremove unreacted phosgene. The purged mixture is then filtered torecover the precipitate. The precipitate is then recrystallized to yieldthe desired product 5-methyl-1,3,4-thiadiazol-2-yl isocyanate dimer.

EXAMPLE 2 Preparation of the Dimethyl Acetal of2-[1-Methyl-3-(5-methyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde

A mixture of 5-methyl-1,3,4-thiadiazol-2-yl isocyanate dimer (0.05mole), the dimethyl acetal of 2-methylaminoacetaldehyde (0.1 mole) andbenzene (60 ml) are charged into a glass reaction vessel equipped with amechanical stirrer and reflux condenser. The reaction mixture is heatedat reflux for a period of about 15 minutes. After this time the mixtureis stripped of benzene under reduced pressure to yield a solid productas the residue. The residue is then recrystallized to yield the desiredproduct the dimethyl acetal of2-[1-methyl-3-(5-methyl-1,3,4-thiadiazol-2-yl)-ureido]acetaldehyde.

EXAMPLE 3 Preparation of1-(5-Methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-one

The dimethyl acetal of2-[1-methyl-3-(5-methyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde (15grams), water (400 ml) and hydrochloric acid (4 ml) are charged into aglass reaction vessel equipped with a mechanical stirrer, thermometerand reflux condenser. The reaction mixture is heated at reflux for aperiod of about 15 minutes. The reaction mixture is then filtered whilehot and the filtrate is cooled to form a precipitate. The precipitate isrecovered by filtration, is dried and is recrystallized to yield thedesired product1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-one.

EXAMPLE 4 Preparation of1-(5-Methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-acetyloxy-1,3-imidazolidin-2-one

1-(5-Methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-one(0.2 mole), acetic anhydride (0.25 mole), toluenesulfonic acid (0.1gram) and benzene (300 ml) are charged into a glass reaction vesselequipped with a mechanical stirrer and thermometer. The reaction mixtureis heated on a steam bath with stirring for a period of about 2 hours.After this time the reaction mixture is cooled to room temperature andis stripped of solvent under reduced pressure leaving a residue. Theresidue is recrystallized to yield the desired product1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-acetyloxy-1,3-imidazolidin-2-one.

EXAMPLE 5 Preparation of 5-Methoxy-1,3,4-thiadiazol-2-yl IsocyanateDimer

A saturated solution of phosgene in ethyl acetate (100 ml) is chargedinto a glass reaction vessel equipped with a mechanical stirrer. Aslurry of 5-methoxy-2-amino-1,3,4-thiadiazole (40 grams) in ethylacetate (300 ml) is added to the reaction vessel and the resultingmixture is stirred for a period of about 16 hours, resulting in theformation of a precipitate. The reaction mixture is then purged withnitrogen gas to remove unreacted phosgene. The purged mixture is thenfiltered to recover the precipitate. The precipitate is thenrecrystallized to yield the desired product5-methoxy-1,3,4-thiadiazol-2-yl isocyanate dimer.

EXAMPLE 6 Preparation of the Dimethyl Acetal of2-[1-Ethyl-3-(5-methoxy-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde

A mixture of 5-methoxy-1,3,4-thiadiazol-2-yl isocyanate dimer (0.05mole), the dimethyl acetal of 2-ethylaminoacetaldehyde (0.1 mole) andbenzene (60 ml) are charged into a glass reaction vessel equipped with amechanical stirrer and reflux condenser. The reaction mixture is heatedat reflux for a period of about 15 minutes. After this time the mixtureis stripped of benzene under reduced pressure to yield a solid productas the residue. The residue is then recrystallized to yield the desiredproduct the dimethyl acetal of2-[1-ethyl-3-(5-methoxy-1,3,4-thiadiazol-2-yl)-ureido]acetaldehyde.

EXAMPLE 7 Preparation of1-(5-Methoxy-1,3,4-thiadiazol-2-yl)-3-ethyl-5-hydroxy-1,3-imidazolidin-2-one

The dimethyl acetal of2-[1-ethyl-3-(5-methoxy-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde (15grams), water (400 ml) and hydrochloric acid (4 ml) are charged into aglass reaction vessel equipped with a mechanical stirrer, thermometerand reflux condenser. The reaction mixture is heated at reflux for aperiod of about 15 minutes. The reaction mixture is then filtered whilehot and the filtrate is cooled to form a precipitate. The precipitate isrecovered by filtration, is dried and is recrystallized to yield thedesired product1-(5-methoxy-1,3,4-thiadiazol-2-yl)-3-ethyl-5-hydroxy-1,3-imidazolidin-2-one.

EXAMPLE 8 Preparation of1-(5-Methoxy-1,3,4-thiadiazol-2-yl)-3-ethyl-5-acryloxyloxy-1,3-imidazolidin-2-one

1-(5-Methoxy-1,3,4-thiadiazol-2-yl)-3-ethyl-5-hydroxy-1,3-imidazolidin-2-one(0.2 mole), acrylic anhydride (0.25 mole), toluenesulfonic acid (0.1gram) and benzene (300 ml) are charged into a glass reaction vesselequipped with a mechanical stirrer and thermometer. The reaction mixtureis heated on a steam bath with stirring for a period of about 2 hours.After this time the reaction mixture is cooled to room temperature andis stripped of solvent under reduced pressure leaving a residue. Theresidue is recrystallized to yield the desired product1-(5-methoxy-1,3,4-thiadiazol-2-yl)-3-ethyl-5-acryloyloxy-1,3-imidazolidin-2-one.

EXAMPLE 9 Preparation of 5-Methylthio-1,3,4-thiadiazol-2-yl IsocyanateDimer

A saturated solution of phosgene in ethyl acetate (100 ml) is chargedinto a glass reaction vessel equipped with a mechanical stirrer. Aslurry of 5-methylthio-2-amino-1,3,4-thiadiazole (45 grams) in ethylacetate (300 ml) is added to the reaction vessel and the resultingmixture is stirred for a period of about 16 hours, resulting in theformation of a precipitate. The reaction mixture is then purged withnitrogen gas to remove unreacted phosgene. The purged mixture isfiltered to recover the precipitate. The precipitate is thenrecrystallized to yield the desired product5-methylthio-1,3,4-thiadiazol-2-yl isocyanate dimer.

EXAMPLE 10 Preparation of the Dimethyl Acetal of2-[1-Propyl-3-(5-methylthio-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde

A mixture of 5-methylthio-1,3,4-thiadiazol-2-yl isocyanate dimer (0.05mole), the dimethyl acetal of 2-propylaminoacetaldehyde (0.1 mole) andbenzene (60 ml) are charged into a glass reaction vessel equipped with amechanical stirrer and reflux condenser. The reaction mixture is heatedat reflux for a period of about 15 minutes. After this time the mixtureis stripped of benzene under reduced pressure to yield a solid productas the residue. The residue is then recrystallized to yield the desiredproduct the dimethyl acetal of2-[1-propyl-3-(5-methylthio-1,3,4-thiadiazol-2-yl)-ureido]acetaldehyde.

EXAMPLE 11 Preparation of1-(5-Methylthio-1,3,4-thiadiazol-2-yl)-3-propyl-5-hydroxy-1,3-imidazolidin-2-one

The dimethyl acetal of2-[1-propyl-3-(5-methylthio-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde(15 grams), water (400 ml) and hydrochloric acid (4 ml) are charged intoa glass reaction vessel equipped with a mechanical stirrer, thermometerand reflux condenser. The reaction mixture is heated at reflux for aperiod of about 15 minutes. The reaction mixture is then filtered whilehot and the filtrate is cooled to form a precipitate. The precipitate isrecovered by filtration, is dried and is recrystallized to yield thedesired product1-(5-methylthio-1,3,4-thiadiazol-2-yl)-3-propyl-5-hydroxy-1,3-imidazolidin-2-one.

EXAMPLE 12 Preparation of1-(5-Methylthio-1,3,4-thiadiazol-2-yl)-3-propyl-5-chloroacetyloxy-1,3-imidazolidin-2-one

1-(5-Methylthio-1,3,4-thiadiazol-2-yl)-3-propyl-5-hydroxy-1,3-imidazolidin-2-one(0.2 mole), chloroacetic anhydride (0.25 mole), toluenesulfonic acid(0.1 gram) and benzene (300 ml) are charged into a glass reaction vesselequipped with a mechanical stirrer and thermometer. The reaction mixtureis heated on a steam bath with stirring for a period of about 2 hours.After this time the reaction mixture is cooled to room temperature andis stripped of solvent under reduced pressure leaving a residue. Theresidue is recrystallized to yield the desired product1-(5-methylthio-1,3,4-thiadiazol-2-yl)-3-propyl-5-chloroacetyloxy-1,3-imidazolidin-2-one.

EXAMPLE 13 Preparation of 5-Methylsulfonyl-1,3,4-thiadiazol-2-ylIsocyanate Dimer

A saturated solution of phosgene in ethyl acetate (100 ml) is chargedinto a glass reaction vessel equipped with a mechanical stirrer. Aslurry of 5-methylsulfonyl-2-amino-1,3,4-thiadiazole (50 grams) in ethylacetate (300 ml) is added to the reaction vessel and the resultingmixture is stirred for a period of about 16 hours, resulting in theformation of a precipitate. The reaction mixture is then purged withnitrogen gas to remove unreacted phosgene. The purged mixture is thenfiltered to recover the precipitate. The precipitate is thenrecrystallized to yield the desired product5-methylsulfonyl-1,3,4-thiadiazol-2-yl isocyanate dimer.

EXAMPLE 14 Preparation of the Dimethyl Acetal of2-[1-Allyl-3-(5-methylsulfonyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde

A mixture of 5-methylsulfonyl-1,3,4-thiadiazol-2-yl isocyanate dimer(0.05 mole), the dimethyl acetal of 2-allylaminoacetaldehyde (0.1 mole)and benzene (60 ml) are charged into a glass reaction vessel equippedwith a mechanical stirrer and reflux condenser. The reaction mixture isheated at reflux for a period of about 15 minutes. After this time themixture is stripped of benzene under reduced pressure to yield a solidproduct as the residue. The residue is then recrystallized to yield thedesired product the dimethyl acetal of2-[1-allyl-3-(5-methylsulfonyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde.

EXAMPLE 15 Preparation of1-(5-Methylsulfonyl-1,3,4-thiadiazol-2-yl)-3-allyl-5-hydroxy-1,3-imidazolidin-2-one

The dimethyl acetal of2-[1-allyl-3-(5-methylsulfonyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde(15 grams), water (400 ml) and hydrochloric acid (4 ml) are charged intoa glass reaction vessel equipped with a mechanical stirrer, thermometerand reflux condenser. The reaction mixture is heated at reflux for aperiod of about 15 minutes. The reaction mixture is then filtered whilehot and the filtrate is cooled to form a precipitate. The precipitate isrecovered by filtration, is dried and is recrystallized to yield thedesired product1-(5-methylsulfonyl-1,3,4-thiadiazol-2-yl)-3-allyl-5-hydroxy-1,3-imidazolidin-2-one.

EXAMPLE 16 Preparation of1-(5-Methylsulfonyl-1,3,4-thiadiazol-2-yl)-3-allyl-5-cyclohexylcarbonyloxy-1,3-imidazolidin-2-one

1-(5-Methylsulfonyl-1,3,4-thiadiazol-2-yl)-3-allyl-5-hydroxy-1,3-imidazolidin-2-one(0.2 mole), cyclohexanecarboxylic anhydride (0.25 mole), toluenesulfonicacid (0.1 gram) and benzene (300 ml) are charged into a glass reactionvessel equipped with a mechanical stirrer and thermometer. The reactionmixture is heated on a steam bath with stirring for a period of about 2hours. After this time the reaction mixture is cooled to roomtemperature and is stripped of solvent under reduced pressure leaving aresidue. The residue is recrystallized to yield the desired product1-(5-methylsulfonyl-1,3,4-thiadiazol-2-yl)-3-allyl-5-cyclohexylcarbonyloxy-1,3-imidazolidin-2-one.

EXAMPLE 17 Preparation of 5-Methylsulfinyl-1,3,4-thiadiazol-2-ylIsocyanate Dimer

A saturated solution of phosgene in ethyl acetate (100 ml) is chargedinto a glass reaction vessel equipped with a mechanical stirrer. Aslurry of 5-methylsulfinyl-2-amino-1,3,4-thiadiazole (50 grams) in ethylacetate (300 ml) is added to the reaction vessel and the resultingmixture is stirred for a period of about 16 hours, resulting in theformation of a precipitate. The reaction mixture is then purged withnitrogen gas to remove unreacted phosgene. The purged mixture is thenfiltered to recover the precipitate. The precipitate is thenrecrystallized to yield the desired product5-methylsulfinyl-1,3,4-thiadiazol-2-yl isocyanate dimer.

EXAMPLE 18 Preparation of the Dimethyl Acetal of2-[1-Chloromethyl-3-(5-methylsulfinyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde

A mixture of 5-methylsulfinyl-1,3,4-thiadiazol-2-yl isocyanate dimer(0.05 mole), the dimethyl acetal of 2-chloromethylaminoacetaldehyde (0.1mole) and benzene (60 ml) are charged into a glass reaction vesselequipped with a mechanical stirrer and reflux condenser. The reactionmixture is heated at reflux for a period of about 15 minutes. After thistime the mixture is stripped of benzene under reduced pressure to yielda solid product as the residue. The residue is then recrystallized toyield the desired product the dimethyl acetal of2-[1-chloromethyl-3-(5-methylsulfinyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde.

EXAMPLE 19 Preparation of1-(5-Methylsulfinyl-1,3,4-thiadiazol-2-yl)-3-chloromethyl-5-hydroxy-1,3-imidazolidin-2-one

The dimethyl acetal of2-[1-chloromethyl-3-(5-methylsulfinyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde(15 grams), water (400 ml) and hydrochloric acid (4 ml) are charged intoa glass reaction vessel equipped with a mechanical stirrer, thermometerand reflux condenser. The reaction mixture is heated at reflux for aperiod of about 15 minutes. The reaction mixture is then filtered whilehot and the filtrate is cooled to form a precipitate. The precipitate isrecovered by filtration, is dried and is recrystallized to yield thedesired product1-(5-methylsulfinyl-1,3,4-thiadiazol-2-yl)-3-chloromethyl-5-hydroxy-1,3-imidazolidin-2-one.

EXAMPLE 20 Preparation of1-(5-Methylsulfinyl-1,3,4-thiadiazol-2-yl)-3-chloromethyl-5-benzoyloxy-1,3-imidazolidin-2-one

1-(5-Methylsulfinyl-1,3,4-thiadiazol-2-yl)-3-chloromethyl-5-hydroxy-1,3-imidazolidin-2-one(0.2 mole), benzoic anhydride (0.25 mole), toluenesulfonic acid (0.1gram) and benzene (300 ml) are charged into a glass reaction vesselequipped with a mechanical stirrer and thermometer. The reaction mixtureis heated on a steam bath with stirring for a period of about 2 hours.After this time the reaction mixture is cooled to room temperature andis stripped of solvent under reduced pressure leaving a residue. Theresidue is recrystallized to yield the desired product1-(5-methylsulfinyl-1,3,4-thiadiazol-2-yl)-3-chloromethyl-5-benzoyloxy-1,3-imidazolidin-2-one.

EXAMPLE 21 Preparation of 5-Cyclopropyl-1,3,4-thiadiazol-2-yl IsocyanateDimer

A saturated solution of phosgene in ethyl acetate (100 ml) was chargedinto a glass reaction vessel equipped with a mechanical stirrer. Aslurry of 5-cyclopropyl-2-amino-1,3,4-thiadiazole (6 grams) in ethylacetate (100 ml) was added to the reaction vessel and the resultingmixture was stirred for a period of about 16 hours, resulting in theformation of a precipitate. The reaction mixture was then purged withnitrogen gas to remove unreacted phosgene. The purged mixture wasfiltered to recover the desired product5-cyclopropyl-1,3,4-thiadiazol-2-yl isocyanate dimer.

EXAMPLE 22 Preparation of the Dimethyl Acetal of2-[1-Propargyl-3-(5-cyclopropyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde

A mixture of 5-cyclopropyl-1,3,4-thiadiazol-2-yl isocyanate dimer (7grams), the dimethyl acetal of 2-propargylaminoacetaldehyde (5 grams)and ethyl acetate (50 ml) were charged into a glass reaction vesselequipped with a mechanical stirrer and reflux condenser. The reactionmixture is heated at reflux for a period of about 2 hours. After thistime the mixture is stripped of solvent under reduced pressure to yieldthe desired product the dimethyl acetal of2-[1-propargyl-3-(5-cyclopropyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehydeas an oil.

EXAMPLE 23 Preparation of1-(5-Cyclopropyl-1,3,4-thiadiazol-2-yl)-3-propargyl-5-hydroxy-1,3-imidazolidin-2-one

The dimethyl acetal of2-[1-propargyl-3-(5-cyclopropyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehydeobtained from Example 22, water (400 ml) and hydrochloric acid (4 ml)are charged into a glass reaction vessel equipped with a mechanicalstirrer, thermometer and reflux condenser. The reaction mixture isheated at reflux for a period of about 15 minutes. The reaction mixtureis then filtered while hot and the filtrate is cooled to form aprecipitate. The precipitate is recovered by filtration, is dried and isrecrystallized from ethyl acetate to yield the desired product1-(5-cyclopropyl-1,3,4-thiadiazol-2-yl)-3-propargyl-5-hydroxy-1,3-imidazolidin-2-one.

EXAMPLE 24 Preparation of1-(5-Cyclopropyl-1,3,4-thiadiazol-2-yl)-3-propargyl-5-(3-methylbenzoyloxy)-1,3-imidazolidin-2-one

1-(5-Cyclopropyl-1,3,4-thiadiazol-2-yl)-3-propargyl-5-hydroxy-1,3-imidazolidin-2-one(0.2 mole), 3-methylbenzoic anhydride (0.25 mole), toluenesulfonic acid(0.1 gram) and benzene (300 ml) are charged into a glass reaction vesselequipped with a mechanical stirrer and thermometer. The reaction mixtureis heated on a steam bath with stirring for a period of about 2 hours.After this time the reaction mixture is cooled to room temperature andis stripped of solvent under reduced pressure leaving a residue. Theresidue is recrystallized to yield the desired product1-(5-cyclopropyl-1,3,4-thiadiazol-2-yl)-3-propargyl-5-(3-methylbenzoyloxy)-1,3-imidazolidin-2-one.

EXAMPLE 25 Preparation of 5-Cyclohexyl-1,3,4-thiadiazol-2-yl IsocyanateDimer

A saturated solution of phosgene in ethyl acetate (500 ml) is chargedinto a glass reaction vessel equipped with a mechanical stirrer.5-Cyclohexyl-2-amino-1,3,4-thiadiazole (6 grams) is added to thereaction vessel and the resulting mixture is stirred and heated atreflux for a period of about 4 hours, resulting in the formation of aprecipitate. The reaction mixture is then purged with nitrogen gas toremove unreacted phosgene. The purged mixture is then filtered torecover the precipitate. The precipitate is then recrystallized from adimethyl formamide-water mixture to yield the desired product5-cyclohexyl-1,3,4-thiadiazol-2-yl isocyanate dimer having a meltingpoint of 237° to 239° C.

EXAMPLE 26 Preparation of the Dimethyl Acetal of2-[1-Methyl-3-(5-cyclohexyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde

A mixture of 5-cyclohexyl-1,3,4-thiadiazol-2-yl isocyanate dimer (12grams), the dimethyl acetal of 2-methylaminoacetaldehyde (6.9 grams) andbenzene (60 ml) are charged into a glass reaction vessel equipped with amechanical stirrer and reflux condenser. The reaction mixture is heatedat reflux for a period of about 15 minutes. After this time the mixtureis stripped of benzene under reduced pressure to yield a solid productas the residue. The residue is then recrystallized from methanol toyield the desired product the dimethyl acetal of2-[1-methyl-3-(5-cyclohexyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehydehaving a melt point of 133° to 134° C.

EXAMPLE 27 Preparation of1-(5-Cyclohexyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-one

The dimethyl acetal of2-[1-methyl-3-(5-cyclohexyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde(15 grams), water (400 ml) and hydrochloric acid (4 ml) are charged intoa glass reaction vessel equipped with a mechanical stirrer, thermometerand reflux condenser. The reaction mixture is heated at reflux for aperiod of about 15 minutes. The reaction mixture is then filtered whilehot and the filtrate is cooled to form a precipitate. The precipitate isrecovered by filtration, is dried and is recrystallized from methanol toyield the desired product1-(5-cyclohexyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-onehaving a melt point of 154° to 155° C.

EXAMPLE 28 Preparation of1-(5-Cyclohexyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-chlorobenzoyloxy)-1,3-imidazolidin-2-one

1-(5-Cyclohexyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-one(0.2 mole), 4-chlorobenzoic anhydride (0.25 mole), toluenesulfonic acid(0.1 gram) and benzene (300 ml) are charged into a glass reaction vesselequipped with a mechanical stirrer and thermometer. The reaction mixtureis heated on a steam bath with stirring for a period of about 2 hours.After this time the reaction mixture is cooled to room temperature andis stripped of solvent under reduced pressure leaving a residue. Theresidue is recrystallized to yield the desired product1-(5-cyclohexyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-chlorobenzoyloxy)-1,3-imidazolidin-2-one.

EXAMPLE 29 Preparation of 5-Cyclobutyl-1,3,4-thiadiazol-2-yl IsocyanateDimer

A saturated solution of phosgene in ethyl acetate (100 ml) is chargedinto a glass reaction vessel equipped with a mechanical stirrer. Aslurry of 5-cyclobutyl-2-amino-1,3,4-thiadiazole (45 grams) in ethylacetate (300 ml) is added to the reaction vessel and the resultingmixture is stirred for a period of about 16 hours, resulting in theformation of a precipitate. The reaction mixture is then purged withnitrogen gas to remove unreacted phosgene. The purged mixture is thenfiltered to recover the precipitate. The precipitate is thenrecrystallized to yield the desired product5-cyclobutyl-1,3,4-thiadiazol-2-yl isocyanate dimer.

EXAMPLE 30 Preparation of the Dimethyl Acetal of2-[1-(1,1-Dimethylprop-2-ynyl)-3-(5-cyclobutyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde

A mixture of 5-cyclobutyl-1,3,4-thiadiazol-2-yl isocyanate dimer (0.05mole), the dimethyl acetal of 1,1-dimethylprop-2-ynylaminoacetaldehyde(0.1 mole) and benzene (60 ml) are charged into a glass reaction vesselequipped with a mechanical stirrer and reflux condenser. The reactionmixture is heated at reflux for a period of about 15 minutes. After thistime the mixture is stripped of benzene under reduced pressure to yielda solid product as the residue. The residue is then recrystallized toyield the desired product the dimethyl acetal of2-[1-(1,1-dimethylprop-2-ynyl)-3-(5-cyclobutyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde.

EXAMPLE 31 Preparation of1-(5-Cyclobutyl-1,3,4-thiadiazol-2-yl)-3-(1,1-dimethylprop-2-ynyl)-5-hydroxy-1,3-imidazolidin-2-one

The dimethyl acetal of2-[1-(1,1-dimethylprop-2-ynyl)-3-(5-cyclobutyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde(15 grams), water (400 ml) and hydrochloric acid (4 ml) are charged intoa glass reaction vessel equipped with a mechanical stirrer, thermometerand reflux condenser. The reaction mixture is heated at reflux for aperiod of about 15 minutes. The reaction mixture is then filtered whilehot and the filtrate is cooled to form a precipitate. The precipitate isrecovered by filtration, is dried and is recrystallized to yield thedesired product1-(5-cyclobutyl-1,3,4-thiadiazol-2-yl)-3-(1,1-dimethylprop-2-ynyl)-5-hydroxy-1,3-imidazolidin-2-one.

EXAMPLE 32 Preparation of1-(5-Cyclobutyl-1,3,4-thiadiazol-2-yl)-3-(1,1-dimethylprop-2-ynyl)-5-(4-methoxybenzoyloxy)-1,3-imidazolidin-2-one

1-(5-Cyclobutyl-1,3,4-thiadiazol-2-yl)-3-(1,1-dimethylprop-2-ynyl)-5-hydroxy-1,3-imidazolidin-2-one(0.2 mole), 4-methoxybenzoic anhydride (0.25 mole), toluenesulfonic acid(0.1 gram) and benzene (300 ml) are charged into a glass reaction vesselequipped with a mechanical stirrer and thermometer. The reaction mixtureis heated on a steam bath with stirring for a period of about 2 hours.After this time the reaction mixture is cooled to room temperature andis stripped of solvent under reduced pressure leaving a residue. Theresidue is recrystallized to yield the desired product1-(5-cyclobutyl-1,3,4-thiadiazol-2-yl)-3-(1,1-dimethylprop-2-ynyl)-5-(4-methoxybenzoyloxy)-1,3-imidazolidin-2-one.

EXAMPLE 33 Preparation of 5-Cyclopentyl-1,3,4-thiadiazol-2-yl IsocyanateDimer

A saturated solution of phosgene in ethyl acetate (100 ml) is chargedinto a glass reaction vessel equipped with a mechanical stirrer. Aslurry of 5-cyclopentyl-2-amino-1,3,4-thiadiazole (50 grams) in ethylacetate (300 ml) is added to the reaction vessel and the resultingmixture is stirred for a period of about 16 hours, resulting in theformation of a precipitate. The reaction mixture is then purged withnitrogen gas to remove unreacted phosgene. The purged mixture is thenfiltered to recover the precipitate. The precipitate is thenrecrystallized to yield the desired product5-cyclopentyl-1,3,4-thiadiazol-2-yl isocyanate dimer.

EXAMPLE 34 Preparation of the Dimethyl Acetal of2-[1-Methyl-3-(5-cyclopentyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde

A mixture of 5-cyclopentyl-1,3,4-thiadiazol-2-yl isocyanate dimer (0.05mole), the dimethyl acetal of 2-methylaminoacetaldehyde (0.1 mole) andbenzene (60 ml) are charged into a glass reaction vessel equipped with amechanical stirrer and reflux condenser. The reaction mixture is heatedat reflux for a period of about 15 minutes. After this time the mixtureis stripped of benzene under reduced pressure to yield a solid productas the residue. The residue is then recrystallized to yield the desiredproduct the dimethyl acetal of2-[1-methyl-3-(5-cyclopentyl-1,3,4-thiadiazol-2-yl)-ureido]acetaldehyde.

EXAMPLE 35 Preparation of1-(5-Cyclopentyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-one

The dimethyl acetal of2-[1-methyl-3-(5-cyclopentyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde(15 grams), water (400 ml) and hydrochloric acid (4 ml) are charged intoa glass reaction vessel equipped with a mechanical stirrer, thermometerand reflux condenser. The reaction mixture is heated at reflux for aperiod of about 15 minutes. The reaction mixture is then filtered whilehot and the filtrate is cooled to form a precipitate. The precipitate isrecovered by filtration, is dried and is recrystallized to yield thedesired product1-(5-cyclopentyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-one.

EXAMPLE 36 Preparation of1-(5-Cyclopentyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-trifluoromethylbenzoyloxy)-1,3-imidazolidin-2-one

1-(5-Cyclopentyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-one(0.2 mole), triethylamine (0.25 mole) and benzene (300 ml) are chargedinto a glass reaction vessel equipped with a mechanical stirrer,thermometer and reflux condenser. 4-Trifluoromethylbenzoyl chloride(0.21 mole) is added dropwise with stirring. After the addition iscompleted the reaction mixture is heated at reflux, with continuedstirring for a period of about 45 minutes. After this time the reactionmixture is filtered and the filtrate is stripped of solvent underreduced pressure to yield a solid residue. This residue isrecrystallized to yield the desired poroduct1-(5-cyclopentyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-trifluoromethylbenzoyloxy)-1,3-imidazolidin-2-one.

EXAMPLE 37 Preparation of 5-Chloromethyl-1,3,4-thiadiazol-2-ylIsocyanate Dimer

A saturated solution of phosgene in ethyl acetate (100 ml) is chargedinto a glass reaction vessel equipped with a mechanical stirrer. Aslurry of 5-chloromethyl-2-amino-1,3,4-thiadiazole (10 grams) in ethylacetate (300 ml) is added to the reaction vessel and the resultingmixture is stirred for a period of about 16 hours resulting in theformation of a precipitate. The reaction mixture is then purged withnitrogen gas to remove unreacted phosgene. The purged mixture is thenfiltered to recover the desired product5-chloromethyl-1,3,4-thiadiazol-2-yl isocyanate dimer as a solid.

EXAMPLE 38 Preparation of the Dimethyl Acetal of2-[1-Methyl-3-(5-chloromethyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde

A mixture of 5-chloromethyl-1,3,4-thiadiazol-2-yl isocyanate dimer (9.5grams), the dimethyl acetal of 2-methylaminoacetaldehyde (5.8 grams) andbenzene (60 ml) are charged into a glass reaction vessel equipped with amechanical stirrer and reflux condenser. The reaction mixture is heatedat reflux for a period of about 15 minutes. After thIs time the mixtureis stripped of benzene under reduced pressure to yield a solid productas the residue. This product is recrystallized to yield the desiredproduct the dimethyl acetal of2-[1-methyl-3-(5-chloromethyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde.

EXAMPLE 39 Preparation of1-(5-Chloromethyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-one

The dimethyl acetal of2-[1-methyl-3-(5-chloromethyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde(15 grams), water (400 ml) and hydrochloric acid (4 ml) are charged intoa glass reaction vessel equipped with a mechanical stirrer, thermometerand reflux condenser. The reaction mixture is heated at reflux for aperiod of about 15 minutes. The reaction mixture is then filtered whilehot and the filtrate is cooled resulting in the formation of aprecipitate. The precipitate is recovered by filtration, is dried and isrecrystallized from an ethyl acetate-hexane mixture to yield the desiredproduct1-(5-chloromethyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-one.

EXAMPLE 40 Preparation of1-(5-Chloromethyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-methylthiobenzoyloxy)-1,3-imidazolidin-2-one

1-(5-Chloromethyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-one(0.2 mole), triethylamine (0.25 mole) and benzene (300 ml) are chargedinto a glass reaction vessel equipped with a mechanical stirrer,thermometer and reflux condenser. 4-Methylthiobenzoyl chloride (0.21mole) is added dropwise with stirring. After the addition is completedthe reaction mixture is heated at reflux, with continued stirring for aperiod of about 45 minutes. After this time the reaction mixture isfiltered and the filtrate is stripped of solvent under reduced pressureto yield a solid residue. This residue is recrystallized to yield thedesired product1-(5-chloromethyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-methylthiobenzoyloxy)-1,3-imidazolidin-2-one.

EXAMPLE 41 Preparation of 5-Allyl-1,3,4-thiadiazol-2-yl Isocyanate Dimer

A saturated solution of phosgene in ethyl acetate (100 ml) is chargedinto a glass reaction vessel equipped with a mechanical stirrer. Aslurry of 5-allyl-2-amino-1,3,4-thiadiazole (50 grams) in ethyl acetate(300 ml) is added to the reaction vessel and the resulting mixture isstirred for a period of about 16 hours, resulting in the formation of aprecipitate. The reaction mixture is then purged with nitrogen gas toremove unreacted phosgene. The purged mixture is then filtered torecover the precipitate. The precipitate is then recrystallized to yieldthe desired product 5-allyl-1,3,4-thiadiazol-2-yl isocyanate dimer.

EXAMPLE 42 Preparation of the Dimethyl Acetal of2-[1-Methyl-3-(5-allyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde

A mixture of 5-allyl-1,3,4-thiadiazol-2-yl isocyanate dimer (0.05 mole),the dimethyl acetal of 2-methylaminoacetaldehyde (0.1 mole) and benzene(60 ml) are charged into a glass reaction vessel equipped with amechanical stirrer and reflux condenser. The reaction mixture is heatedat reflux for a period of about 15 minutes. After this time the mixtureis stripped of benzene under reduced pressure to yield a solid productas the residue. The residue is then recrystallized to yield the desiredproduct the dimethyl acetal of2-[1-methyl-3-(5-allyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde.

EXAMPLE 43 Preparation of1-(5-Allyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-one

The dimethyl acetal of2-[1-methyl-3-(5-allyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde (15grams), water (400 ml) and hydrochloric acid (4 ml) are charged into aglass reaction vessel equipped with a mechanical stirrer, thermometerand reflux condenser. The reaction mixture is heated at reflux for aperiod of about 15 minutes. The reaction mixture is then filtered whilehot and the filtrate is cooled to form a precipitate. The precipitate isrecovered by filtration, is dried and is recrystallized to yield thedesired product1-(5-allyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-one.

EXAMPLE 44 Preparation of1-(5-Allyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-acetyloxy-1,3-imidazolidin-2-one

1-(5-Allyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-one(0.2 mole), triethylamine (0.25 mole) and benzene (300 ml) are chargedinto a glass reaction vessel equipped with a mechanical stirrer,thermometer and reflux condenser. Acetyl chloride (0.21 mole) is addeddropwise with stirring. After the addition is completed the reactionmixture is heated at reflux, with continued stirring for a period ofabout 45 minutes. After this time the reaction mixture is filtered andthe filtrate is stripped of solvent under reduced pressure to yield asolid residue. This residue is recrystallized to yield the desiredproduct1-(5-allyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-acetyloxy-1,3-imidazolidin-2-one.

EXAMPLE 45 Preparation of1-(5-Methoxy-1,3,4-thiadiazol-2-yl)-3-ethyl-5-methoxyacetyloxy-1,3-imidazolidin-2-one

1-(5-Methoxy-1,3,4-thiadiazol-2-yl)-3-ethyl-5-hydroxy-1,3-imidazolidin-2-one(0.2 mole), methoxyacetic anhydride (0.25 mole), toluenesulfonic acid(0.1 gram) and benzene (300 ml) are charged into a glass reaction vesselequipped with a mechanical stirrer and thermometer. The reaction mixtureis heated on a steam bath with stirring for a period of about 2 hours.After this time the reaction mixture is cooled to room temperature andis stripped of solvent under reduced pressure leaving a residue. Theresidue is recrystallized to yield the desired product1-(5-methoxy-1,3,4-thiadiazol-2-yl)-3-ethyl-5-methoxyacetyloxy-1,3-imidazolidin-2-one.

EXAMPLE 46 Preparation of1-(5-Cyclopropyl-1,3,4-thiadiazol-2-yl)-3-propargyl-5-(3-methylphenylacetyloxy)-1,3-imidazolidin-2-one

1-(5-Cyclopropyl-1,3,4-thiadiazol-2-yl)-3-propargyl-5-hydroxy-1,3-imidazolidin-2-one(0.2 mole), 3-methylphenylacetic anhydride (0.25 mole), toluenesulfonicacid (0.1 gram) and benzene (300 ml) are charged into a glass reactionvessel equipped with a mechanical stirrer and thermometer. The reactionmixture is heated on a steam bath with stirring for a period of about 2hours. After this time the reaction mixture is cooled to roomtemperature and is stripped of solvent under reduced pressure leaving aresidue. The residue is recrystallized to yield the desired product1-(5-cyclopropyl-1,3,4-thiadiazol-2-yl)-3-propargyl-5-(3-methylphenylacetyloxy)-1,3-imidazolidin-2-one.

EXAMPLE 47 Preparation of1-(5-Methylthio-1,3,4-thiadiazol-2-yl)-3-propyl-5-propynoyloxy-1,3-imidazolidin-2-one

1-(5-Methylthio-1,3,4-thiadiazol-2-yl)-3-propyl-5-hydroxy-1,3-imidazolidin-2-one(0.2 mole), propynoic anhydride (0.25 mole), toluenesulfonic acid (0.1gram) and benzene (300 ml) are charged into a glass reaction vesselequipped with a mechanical stirrer and thermometer. The reaction mixtureis heated on a steam bath with stirring for a period of about 2 hours.After this time the reaction mixture is cooled to room temperature andis stripped of solvent under reduced pressure to yield the desiredproduct1-(5-methylthio-1,3,4-thiadiazol-2-yl)-3-propyl-5-propynoyloxy-1,3-imidazolidin-2-one.

EXAMPLE 48 Preparation of1-(5-Methylthio-1,3,4-thiadiazol-2-yl)-3-propyl-5-(3-cyanobenzoyloxy)-1,3-imidazolidin-2-one

1-(5-Methylthio-1,3,4-thiadiazol-2-yl)-3-propyl-5-hydroxy-1,3-imidazolidin-2-one(0.2 mole), 3-cyanobenzoic anhydride (0.25 mole), toluenesulfonic acid(0.1 gram) and benzene (300 ml) are charged into a glass reaction vesselequipped with a mechanical stirrer and thermometer. The reaction mixtureis heated on a steam bath with stirring for a period of about 2 hours.After this time the reaction mixture is cooled to room temperature andis stripped of solvent under reduced pressure leaving a residue. Theresidue is recrystallized to yield the desired product1-(5-methylthio-1,3,4-thiadiazol-2-yl)-3-propyl-5-(3-cyanobenzoyloxy)-1,3-imidazolidin-2-one.

EXAMPLE 49 Preparation of1-(5-Methylthio-1,3,4-thiadiazol-2-yl)-3-propyl-5-(4-nitrobenzoyloxy)-1,3-imidazolidin-2-one

1-(5-Methylthio-1,3,4-thiadiazol-2-yl)-3-propyl-5-hydroxy-1,3-imidazolidin-2-one(0.2 mole), 4-nitrobenzoic anhydride (0.25 mole), toluenesulfonic acid(0.1 gram) and benzene (300 ml) are charged into a glass reaction vesselequipped with a mechanical stirrer and thermometer. The reaction mixtureis heated on a steam bath with stirring for a period of about 2 hours.After this time the reaction mixture is cooled to room temperature andis stripped of solvent under reduced pressure leaving a residue. Theresidue is recrystallized to yield the desired product1-(5-methylthio-1,3,4-thiadiazol-2-yl)-3-propyl-5-(4-nitrobenzoyloxy)-1,3-imidazolidin-2-one.

Additional compounds within the scope of this invention which can beprepared by the procedures detailed in the foregoing examples are1-(5-ethyl-1,3,4-thiadiazol-2-yl)-3-ethyl-5-acetyloxy-1,3-imidazolidin-2-one,1-(5-propyl-1,3,4-thiadiazol-2-yl)-3-propyl-5-propanoyloxy-1,3-imidazolidin-2-one,1-(5-butyl-1,3,4-thiadiazol-2-yl)-3-butyl-5-butanoyloxy-1,3-imidazolidin-2-one,1-(5-pentyl-1,3,4-thiadiazol-2-yl)-3-pentyl-5-pentanoyloxy-1,3-imidazolidin-2-one,1-(5-hexyl-1,3,4-thiadiazol-2-yl)-3-hexyl-5-hexanoyloxy-1,3-imidazolidin-2-one,1-(5-cycloheptyl-1,3,4-thiadiazol-2-yl)-3-but-3-enyl-5-pent-4-enoyloxy-1,3-imidazolidin-2-one,1-(5-but-2-enyl-1,3,4-thiadiazol-2-yl)-3-pent-4-enyl-5-hex-4-enoyloxy-1,3-imidazolidin-2-one,1-(5-pent-3-enyl-1,3,4-thiadiazol-2-yl)-3-hex-5-enyl-5-α-chloroacetyloxy-1,3-imidazolidin-2-one,1-(5-hex-4-enyl-1,3,4-thiadiazol-2-yl)-3-α-chloroethyl-5-β-bromobutanoyloxy-1,3-imidazolidin-2-one,1-(5-β-chloroethyl-1,3,4-thiadiazol-2-yl)-3-iodomethyl-5-γ-chloropentanoyloxy-1,3-imidazolidin-2-one,1-(5-γ-chloropropyl-1,3,4-thiadiazol-2-yl)-3-trifluoromethyl-5-.omega.-chlorohexanoyloxy-1,3-imidazolidin-2-one,1-(5-bromomethyl-1,3,4-thiadiazol-2-yl)-3-β-chloroethyl-5-α-iodoacetyloxy-1,3-imidazolidin-2-one,1-(5-β-bromomethyl-1,3,4-thiadiazol-2-yl)-3-γ-bromopropyl-5-cyclopropylcarbonyloxy-1,3-imidazolidin-2-one,1-(5-trichloromethyl-1,3,4-thiadiazol-2-yl)-3-γ-bromohexyl-5-cyclobutylcarbonyloxy-1,3-imidazolidin-2-one,1-(5-ω-chlorohexyl-1,3,4-thiadiazol-2-yl)-3-β-chlorohexyl-5-cyclopentylcarbonyloxy-1,3-imidazolidin-2-one,1-(5-ethoxy-1,3,4-thiadiazol-2-yl)-3-(1,1-diethylprop-2-ynyl)-5-cycloheptylcarbonyloxy-1,3-imidazolidin-2-one,1-(5-butoxy-1,3,4-thiadiazol-2-yl)-3-(1,1-dipropylprop-2-ynyl)-5-(2-ethylbenzoyloxy)-1,3-imidazolidin-2-one,1-(5-hexyloxy-1,3,4-thiadiazol-2-yl)-3-methyl-5-(3-propylbenzoyloxy)-1,3-imidazolidin-2-one,1-(5-ethylthio-1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-hexylbenzoyloxy)-1,3-imidazolidin-2-one,1-(5-propylthio-1,3,4-thiadiazol-2-yl)-3-methyl-5-(3-ethoxybenzoyloxy)-1,3-imidazolidin-2-one,1-(5-pentylthio-1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-butoxybenzoyloxy)-1,3-imidazolidin-2-one,1-(5-hexylthio-1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-hexyloxybenzoyloxy)-1,3-imidazolidin-2-one,1-(5-ethylsulfonyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-bromobenzoyloxy)-1,3-imidazolidin-2-one,1-(5-propylsulfonyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-iodobenzoyloxy)-1,3-imidazolidin-2-one,1-(5-pentylsulfonyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-fluorobenzoyloxy)-1,3-imidazolidin-2-one,1-(5-hexylsulfonyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(2,4-dichlorobenzoyloxy)-1,3-imidazolidin-2-one,1-(5-ethylsulfinyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(2,4,6-trichlorobenzoyloxy)-1,3-imidazolidin-2-one,1-(5-propylsulfinyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(3,4-dibromobenzoyloxy)-1,3-imidazolidin-2-one,1-(5-butylsulfinyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-trifluoromethylbenzoyloxy)-1,3-imidazolidin-2-one,1-(5-hexylsulfinyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-chloromethylbenzoyloxy)-1,3-imidazolidin-2-one,1-(5-isopropyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-alkylthiobenzoyloxy-1,3-imidazolidin-2-one,1-(5-isopropyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-propylthiobenzoyloxy-1,3-imidazolidin-2-one,1-(5-isopropyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-pentylthiobenzoyloxy-1,3-imidazolidin-2-one,1-(5-isopropyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hexylthiobenzoyloxy-1,3-imidazolidin-2-one,1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-butynoyloxy-1,3-imidazolidin-2-one,1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-pent-4-ynyloxy-1,3-imidazolidin-2-one,1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hex-4-ynyloxy-1,3-imidazolidin-2-one,1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-β-methoxypropionyloxy-1,3-imidazolidin-2-one,1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-γ-methoxybutanoyloxy-1,3-imidazolidin-2-one,1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-δ-methoxypentanoyloxy-1,3-imidazolidin-2-one,1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-β-ethoxypropionyloxy-1,3-imidazolidin-2-one,1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-propoxyacetyloxy-1,3-imidazolidin-2-one,1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-butoxyacetyloxy-1,3-imidazolidin-2-one,1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hexyloxyacetyloxy-1,3-imidazolidin-2-one,1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(3,4-dichlorophenylacetyloxy)-1,3-imidazolidin-2-one,1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-trifluoromethylphenylacetyloxy)-1,3-imidazolidin-2-one,1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(2-methyl-4-chlorophenylacetyloxy)-1,3-imidazolidin-2-one,1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(3-methylthiophenylacetyloxy)-1,3-imidazolidin-2-one,1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(2-methoxyphenylacetyloxy)-1,3-imidazolidin-2-oneand the like.

For practical use as herbicides the compounds of this invention aregenerally incorporated into herbicidal compositions which comprise aninert carrier and a herbicidally toxic amount of such a compound. Suchherbicidal compositions, which can also be called formulations, enablethe active compound to be applied conveniently to the site of the weedinfestation in any desired quantity. These compositions can be solidssuch as dusts, granules, or wettable powders; or they can be liquidssuch as solutions, aerosols, or emulsifiable concentrates.

For example, dusts can be prepared by grinding and blending the activecompound with a solid inert carrier such as the talcs, clays, silicas,pyrophyllite, and the like. Granular formulations can be prepared byimpregnating the compound, usually dissolved in a suitable solvent, ontoand into granulated carriers such as the attapulgites or thevermiculties, usually of a particle size range of from about 0.3 to 1.5mm. Wettable powders, which can be dispersed in water or oil to anydesired concentration of the active compound, can be prepared byincorporating wetting agents into concentrated dust compositions.

In some cases the active compounds are sufficiently soluble in commonorganic solvents such as kerosene or xylene so that they can be useddirectly as solutions in these solvents. Frequently, solutions ofherbicides can be dispersed under super-atmospheric pressure asaerosols. However, preferred liquid herbicidal compositions areemulsifiable concentrates, which comprise an active compound accordingto this invention and as the inert carrier, a solvent and an emulsifier.Such emulsifiable concentrates can be extended with water and/or oil toany desired concentration of active compound for application as spraysto the site of the weed infestation. The emulsifiers most commonly usedin these concentrates are nonionic or mixtures of nonionic with anionicsurface-active agents. With the use of some emulsifier systems aninverted emulsion (water in oil) can be prepared for direct applicationto weed infestations.

A typical herbicidal composition according to this invention isillustrated by the following example, in which the quantities are inparts by weight.

EXAMPLE 50 Preparation of a Dust

Product of Example 4--10

Powdered Talc--90

The above ingredients are mixed in a mechanical grinder-blender and areground until a homogeneous, free-flowing dust of the desired particlesize is obtained. This dust is suitable for direct application to thesite of the weed infestation.

The compounds of this invention can be applied as herbicides in anymanner recognized by the art. One method for the control of weedscomprises contacting the locus of said weeds with a herbicidalcomposition comprising an inert carrier and as an essential activeingredient, in a quantity which is herbicidally toxic to said weeds, acompound of the present invention. The concentration of the newcompounds of this invention in the herbicidal compositions will varygreatly with the type of formulation and the purpose for which it isdesigned, but generally the herbicidal compositions will comprise fromabout 0.05 to about 95 percent by weight of the active compounds of thisinvention. In a preferred embodiment of this invention, the herbicidalcompositions will comprise from about 5 to about 75 percent by weight ofthe active compound. The compositions can also comprise such additionalsubstances as other pesticides, such as insecticides, nematocides,fungicides, and the like; stabilizers, spreaders, deactivators,adhesives, stickers, fertilizers, activators, synergists, and the like.

The compounds of the present invention are also useful when combinedwith other herbicides and/or defoliants, dessicants, growth inhibitors,and the like in the herbicidal compositions heretofore described. Theseother materials can comprise from about 5% to about 95% of the activeingredients in the herbicidal compositions. Use of combinations of theseother herbicides and/or defoliants, dessicants, etc. with the compoundsof the present invention provide herbicidal compositions which are moreeffective in controlling weeds and often provide results unattainablewith separate compositions of the individual herbicides. The otherherbicides, defoliants, dessicants and plant growth inhibitors, withwhich the compounds of this invention can be used in the herbicidalcompositions to control weeds, can include chlorophenoxy herbicides suchas 2,4-D, 2,4,5-T, MCPA, MCPB, 4(2,4-DB), 2,4-DEB, 4-CPB, 4-CPA, 4-CPP,2,4,5-TB, 2,4,5-TES, 3,4-DA, silvex and the like; carbamate herbicidessuch as IPC, CIPC, swep, barban, BCPC, CEPC, CPPC, and the like;thiocarbamate and dithiocarbamate herbicides such as CDEC, methamsodium, EPTC, diallate, PEBC, perbulate, vernolate and the like;substituted urea herbicides such as norea, siduron, dichloral urea,chloroxuron, cycluron, fenuron, monuron, monuron TCA, diuron, linuron,monolinuron, neburon, buturon, trimeturon and the like; symmetricaltriazine herbicides such as simazine, chlorazine, atraone, desmetryne,norazine, ipazine, prometryn, atrazine, trietazine, simetone, prometone,propazine, ametryne and the like; chloroacetamide herbicides such asalpha-chloro-N,N-dimethylacetamide, CDEA, CDAA,alpha-chloro-N-isopropylacetamide, 2-chloro-N-isopropylacetanilide,4-(chloroacetyl)morpholine, 1-(chloroacetyl)-piperidine and the like;chlorinated aliphatic acid herbicides such as TCA, dalapon,2,3-dichloropropionic acid, 2,2,3-TPA and the like; chlorinated benzoicacid and phenylacetic acid herbicides such as 2,3,6-TBA, 2,3,5,6-TBA,dicamba, tricamba, amiben, fenac, PBA,2-methoxy-3,6-dichlorophenylacetic acid,3-methoxy-2,6-dichlorophenylacetic acid,2-methoxy-3,5,6-trichlorophenylacetic acid, 2,4-dichloro-3-nitrobenzoicacid and the like; and such compounds as aminotriazole, maleichydrazide, phenyl mercuric acetate, endothal, biuret, technicalchlordane, dimethyl 2,3,5,6-tetrachloroterephthalate, diquat, erbon,DNC, DNBP, dichlobenil, DPA, diphenamid, dipropalin, trifluralin, solan,dicryl, merphos, DMPA, DSMA, MSMA, potassium azide, acrolein, benefin,bensulide, AMS, bromacil,2-(3,4-dichlorophenyl)-4-methyl-1,2,4-oxadiazolidine-3,5-dione,bromoxynil, cacodylic acid, CMA, CPMF, cypromid, DCB, DCPA, dichlone,diphenatril, DMTT, DNAP, EBEP, EXD, HCA, ioxynil, IPX, isocil, potassiumcyanate, MAA, MAMA, MCPES, MCPP, MH, molinate, NPA, OCH, paraquat, PCP,picloram, DPA, PCA, pyrichlor, sesone, terbacil, terbutol, TCBA,brominil, CP-50144, H-176-1, H-732, M-2901, planavin, sodiumtetraborate, calcium cyanamid, DEF, ethyl xanthogen disulfide, sindone,sindone B, propanil and the like. Such herbicides can also be used inthe methods and compositions of this invention in the form of theirsalts, esters, amides, and other derivatives whenever applicable to theparticular parent compounds.

Weeds are undesirable plants growing where they are not wanted, havingno economic value, and interfering with the production of cultivatedcrops, with the growing of ornamental plants, or with the welfare oflivestock. Many types of weeds are known, including annuals such aspigweed, lambsquarters, foxtail, crabgrass, wild mustard, fieldpennycress, ryegrass, goose grass, chickweed, wild oats, velvetleaf,purslane, barnyardgrass, smartweed, knotweed, cocklebur, wild buckwheat,kochia, medic, corn cockle, ragweed, sowthistle, coffeeweed, croton,cuphea, dodder, fumitory, groundsel, hemp nettle, knawel, spurge,spurry, emex, jungle rice, pondweed, dog fennel, carpetweed,morningglory, bedstraw, ducksalad, naiad, cheatgrass, fall panicum,jimsonweed, witchgrass, switchgrass, watergrass, teaweed, wild turnipand sprangletop; biennials such as wild carrot, matricaria, wild barley,campion, chamomile, burdock, mullein, roundleaved mallow, bull thistle,hounds-tongue, moth mullein and purple star thistle; or perennials suchas white cockle, perennial ryegrass, quackgrass, Johnsongrass, Canadathistle, hedge bindweed, Bermuda grass, sheep sorrel, curly dock,nutgrass, field chickweed, dandelion, campanula, field bindweed, Russianknapweed, mesquite, toadflax, yarrow, aster, gromwell, horsetail,ironweed, sesbania, bulrush, cattail, winter-cress, horsenettle,nutsedge, milkweed and sicklepod.

Similarly, such weeds can be classified as broadleaf or grassy weeds. Itis economically desirable to control the growth of such weeds withoutdamaging beneficial plants or livestock.

The new compounds of this invention are particularly valuable for weedcontrol because they are toxic to many species and groups of weeds whilethey are relatively nontoxic to many beneficial plants. The exact amountof compound required will depend on a variety of factors, including thehardiness of the particular weed species, weather, type of soil, methodof application, the kind of beneficial plants in the same area and thelike. Thus, while the application of up to only about one or two ouncesof active compound per acre may be sufficient for good control of alight infestation of weeds growing under adverse conditions, theapplication of ten pounds or more of an active compound per acre may berequired for good control of a dense infestation of hardy perennialweeds growing under favorable conditions.

The herbicidal toxicity of the new compounds of this invention can bedemonstrated by the following established testing techniques known tothe art, pre- and post-emergence testing.

The herbicidal activity of the compounds of this invention can bedemonstrated by experiments carried out for the pre-emergence control ofa variety of weeds. In these experiments small plastic greenhouse potsfilled with dry soil are seeded with the various weed seeds. Twenty-fourhours or less after seeding the pots are sprayed with water until thesoil is wet and a test compound formulated as an aqueous emulsion of anacetone solution containing emulsifiers is sprayed at the desiredconcentrations on the surface of the soil.

After spraying, the soil containers are placed in the greenhouse andprovided with supplementary heat as required and daily or more frequentwatering. The plants are maintained under these conditions for a periodof from 15 to 21 days, at which time the condition of the plants and thedegree of injury to the plants is rated on a scale of from 0 to 10, asfollows: 0=no injury, 1,2=slight injury, 3,4=moderate injury,5,6=moderately severe injury, 7,8,9=severe injury and 10=death.

The herbicidal activity of the compounds of this invention can also bedemonstrated by experiments carried out for the post-emergence controlof a variety of weeds. In these experiments the compounds to be testedare formulated as aqueous emulsions and sprayed at the desired dosage onthe foliage of the weeds that have attained a prescribed size. Afterspraying the plants are placed in a greenhouse and watered daily or morefrequently. Water is not applied to the foliage of the treated plants.The severity of the injury is determined 10 to 15 days after treatmentand is rated on the scale of from 0 to 10 heretofore described.

I claim:
 1. A compound of the formula ##STR17## wherein R¹ is selectedfrom the group consisting of alkyl of up to 3 carbon atoms, cycloalkylof from 3 to 7 carbon atoms, lower alkenyl, lower chloroalkyl, lowerbromoalkyl, lower alkoxy, lower alkylthio, lower alkylsulfonyl and loweralkylsulfinyl; R² is selected from the group consisting of lower alkyl,lower alkenyl, lower haloalkyl and ##STR18## wherein R⁴ and R⁵ are eachselected from the group consisting of hydrogen and alkyl of up to 3carbon atoms; and R³ is selected from the group consisting of loweralkenyl, lower haloalkyl, lower alkynyl, lower alkoxyalkyl, cycloalkylof from 3 to 7 carbon atoms and ##STR19## wherein X is selected from thegroup consisting of lower alkyl, lower alkoxy, halogen, lower haloalkyl,nitro, cyano and lower alkylthio; n is an integer from 0 to 3; and m isthe integer 0 or
 1. 2.1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-acetyloxy-1,3-imidazolidin-2-one.3. The compound of claim 1,1-(5-methoxy-1,3,4-thiadiazol-2-yl)-3-ethyl-5-acryloyloxy-1,3-imidazolidin-2-one.4. The compound of claim 1,1-(5-methylthio-1,3,4-thiadiazol-2-yl)-3-propyl-5-chloroacetyloxy-1,3-imidazolidin-2-one.5. The compound of claim 1,1-(5-methylsulfonyl-1,3,4-thiadiazol-2-yl)-3-allyl-5-cyclohexylcarbonyloxy-1,3-imidazolidin-2-one.6. The compound of claim 1,1-(5-methylsulfinyl-1,3,4-thiadiazol-2-yl)-3-chloromethyl-5-benzoyloxy-1,3-imidazolidin-2-one.7. The compound of claim 1,1-(5-cyclopropyl-1,3,4-thiadiazol-2-yl)-3-propargyl-5-(3-methylbenzoyloxy)-1,3-imidazolidin-2-one.8. The compound of claim 1,1-(5-cyclohexyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-chlorobenzoyloxy)-1,3-imidazolidin-2-one.9. A herbicidal composition comprising an inert carrier and, as anessential active ingredient, in a quantity toxic to weeds, a compound ofclaim
 1. 10. A method of controlling weeds which comprises contactingsaid weeds with a herbicidal composition comprising an inert carrierand, as an essential active ingredient, in a quantity toxic to weeds, acompound of claim 1.